The present invention relates generally to an absorption plate for an air conditioner mounted on an automobile.
Devises for air conditioning by absorption are known in the prior art. For example, document FR 2 941 773 describes an air conditioner by absorption comprising absorption plates in which an absorbing fluid, lithium bromide, circulates and absorbs a refrigerating fluid, water vapor. On the other hand, this system has in particular the disadvantage of presenting an efficiency limited by the absorption capacities of the absorbing fluid in the refrigerating fluid. In fact, during the exothermic reaction of absorption on the surface, the absorbing fluid, lithium bromide, in contact with the refrigerating fluid, water vapor, heats up and the surface layer is rapidly saturated with refrigerating fluid. The absorption is limited by the transfer rate toward the center of the heat flow released and/or of the refrigerating fluid. The result is a rather weak total efficiency of the system because the transfer rate (of the heat released and of the refrigerating fluid absorbed) in the direction of the center of the flow of absorbing solution very strongly limits the absorption capacities during the traversing of the plate.
Moreover, the document U.S. Pat. No. 4,223,539 describes another type of air conditioner by absorption in which the absorbing fluid is sprayed onto refrigerating tubes where it flows out and absorbs the refrigerating fluid, and the surface of these tubes comprises protuberances creating a surface turbulence. Such an implementation is expensive because the process for manufacturing protuberances on the surface of a tube is not easy to carry out and its feasibility on an industrial scale has not been demonstrated. Furthermore, this implementation binds the protuberances to the surface on which the fluid is flowing and this makes any modification of the protuberances or of the surface difficult. This also complicates the supplying because the complexity of such a component limits the number of suppliers. Therefore, this implementation cannot be adapted to the automobile area, where flexibility and costs are parameters that direct the design. Finally, the bulkiness of such a system does not allow it to be integrated into a vehicle, when the geometric limitations of the vehicle are taken in to consideration.